Research is continuing but is hoped to improve our understanding of the association between defects in the cellular immune system and disease. When an immunological response is made powerful inflammatory changes follow. Recently, much interest has been aroused in evidence which would suggest that in some humans the control of these powerful inflammatory forces is inappropriate. One of the two major components of the immune system is known as cell mediated immunity and it is this form of immunity which is strongly involved in protecting humans from cancer and other malignancies, viral infections and fungal infections. Control of the effector cells for cell mediated immunity is in the hands of a thymus derived lymphocyte known as a suppressor or immunoregulatory T cell. The study of this cell has been facilitated by the discovery that it can be stimulated in vitro to perform its immunoregulatory functions by a mitogenic extract, Concanavalin A. The work of this project involves studies designed to improve the in vitro assay for normal immunoregulatory activity so that the limits of normal behavior can be accurately defined and then applying the techniques to the study of human diseases in which an immunoregulatory defect seems possible. Such diseases include various forms of agammaglobulinemia and autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. We are currently applying these techniques to the study of hepatitis, multiple sclerosis, sarcoidosis, idiopathic thrombocytopenic purpura and chronic fungal infections. We are also seeking beneficial effects of transfer factor, an extract from competent immunocytes, on immunoregulatory cells.